U.S. Pat. No. 3,444,506 describes a multicontact electrical connector for flat cable having contact terminals therein which have wire receiving slots into which the conductors of the cable are inserted when electrical contact is made. The terminals are of flat conductive sheet metal and have a free end into which the wire receiving slot extends. The width of the slot is less than the conducting cores of the conductors so that as the conductor moves into the slot, the edges of the slot contact the conductor to form the electrical contact.
Terminals of the type described in the above-identified U.S. patent are widely used for wires having a diameter of at least 0.33 mm (0.013 inches) which is the equivalent of an AWG 28 wire, but they are not used to any significant extent for wires having a diameter less than 0.33 mm. Consequently, as the dimensions of the terminals are sufficient, retention members can be provided which cooperate with the connector to positively retain the terminals in the connector. Also, in a terminal of this size, tolerances can be easily provided, so that a mating connector does not have to be precisely aligned when the mating connector is mated to the connector (i.e. some slight alignment will be provided due to the tolerances of the terminals of the connector).
The reason for the limitation on the use of wire-in-slot or insulation displacement terminals with larger wires is that it is impractical to produce terminals having extremely narrow slots which are required for very fine wires. For example, an AWG 32 wire has a diameter of about 0.20 mm (0.008 inches) and the slot required for a wire of this size must have a width of about 0.1 mm (0.004 inches). The wire receiving slots of the terminals disclosed in U.S. Pat. No. 3,444,506 are produced in the sheet metal from which the terminals are manufactured by means of conventional punch and die techniques (a punch is provided having an opening into which the punch moves). The sheet metal is supported on the die and when the punch moves into the die, the slot is formed. As a practical matter, it is not possible to produce slots in sheet metal of a given thickness which have a width which is significantly less than the thickness of the sheet metal.
U.S. Pat. No. 4,600,259 discloses a terminal which has a wire receiving slot which is not manufactured by the standard punch and die techniques. Instead, the wire receiving slot is a folded section of sheet metal, which produces a pair of parallel platelike members which cooperate with the wires. The configuration of the terminals are more compact than previously available, and for that reason, are desirable for use with extremely fine wires.
These more compact terminals, when placed in a multicontact connector, provide an accurate means for terminating ribbon cable which has extremely close centerline spacing. However, several problems occur when these terminals are positioned in a connector housing. With such compact terminals and the close spacing that is required, the tolerances associated with the terminals becomes critical. As the compact nature of the terminals does not allow for large tolerances, a mating pin inserted into the pin receiving area of the terminal must be accurately aligned in order to avoid stubbing, etc. Also, due to the compact nature of the terminals, the frictional engagement between the terminals and the walls of the cavity is not great. Consequently, the retention of the terminals in the connector is insufficient as the able is terminated thereto. However, due to the size of the terminals, it is impractical to add material in order to add retention features. Therefore, a positive retention means, which does not increase the dimensions of the terminal, must be provided in order for the terminals to maintain their position in the connector housing.
The present invention is directed to the achievement of an improved electrical connector which has terminals provided therein which have positive retention means to insure that they are maintained in the connector housing as the cable is terminated thereto. The retention means do not increase the overall size of the terminals, thereby facilitating the close spacing requirements of the connector. The invention is further directed to providing compact terminals which are configured to provide a mating area which can accept slightly misaligned mating contacts therein.